无法关闭Android ProgressDialog

我有一个名为的静态ProgressDialog对象 对话 在我的班级里

dialog = new ProgressDialog(this);

执行此代码

buildGroupAccessDialog(groupName); dialog.show(c, "Joining", "Please wait...");

这些是所涉及的方法

private void builGroupAccessDialog(final String groupName){
    AlertDialog.Builder alertDialogBuilder = new AlertDialog.Builder(this);
    // set title
    alertDialogBuilder.setTitle("Join group");

    // set dialog message
    alertDialogBuilder
            .setMessage("Do you want to join " + groupName + "  ?")
            .setCancelable(false)
            .setPositiveButton("Yes", new DialogInterface.OnClickListener() {
                public void onClick(DialogInterface dialog, int id) {
                    //join group
                    joinGroup(groupName);
                }
            })
            .setNegativeButton("No", new DialogInterface.OnClickListener() {
                public void onClick(DialogInterface dialog, int id) {
                }
            }).create()
            .show();

}

joinGroup()被调用:

private void joinGroup(final String groupName) {
    Log.d("TRY TO JOIN GROUP:", groupName);


    new Thread(new Runnable() {
        @Override
        public void run() {
            //Get the device
            WifiP2pDevice dev = mRecyclerViewFragment.getDeviceMap().get(groupName);

            WifiP2pConfig config = new WifiP2pConfig();

            config.deviceAddress = dev.deviceAddress;


            wifip2pManager.connect(wifiDirectChannel, config, new WifiP2pManager.ActionListener() {

                @Override
                public void onSuccess() {
                    Log.d("CONNECT", "SUCCESS");

                    // This is used for avoiding registering another BroadcastListener on purpose, keeping only one but responding
                    // to intent only when I'm sure I want it
                    iWantToConnect = true;

                    // Hide progress dialog
                    dialog.dismiss();
                }

                @Override
                public void onFailure(int reason) {

                    Log.d("CONNECT", "FAILURE");

                    //Toast.makeText(getApplication(), "PIPPO", Toast.LENGTH_LONG);
                }
            });

        }
    }).start();

}

我有两个问题:

请注意,我说的是 对话 变量

1) “进度对话框”在不等待用户AlertDialog响应的情况下启动(如何使其同步?)

2) 进度对话框未关闭(为什么?)

谢谢

编辑: 我通过以下方式更改了代码:

buildGroupAccessDialog(groupName);

以及:

private void joinGroup(final String groupName) {
    Log.d("TRY TO JOIN GROUP:", groupName);

    dialog.show(this, "Joining", "Please wait...");

    new Thread(new Runnable() {
        @Override
        public void run() {
            //Get the device
            WifiP2pDevice dev = mRecyclerViewFragment.getDeviceMap().get(groupName);

            WifiP2pConfig config = new WifiP2pConfig();

            config.deviceAddress = dev.deviceAddress;


            wifip2pManager.connect(wifiDirectChannel, config, new WifiP2pManager.ActionListener() {

                @Override
                public void onSuccess() {
                    Log.d("CONNECT", "SUCCESS");

                    // This is used for avoiding registering another BroadcastListener on purpose, keeping only one but responding
                    // to intent only when I'm sure I want it
                    iWantToConnect = true;


                    // Togli il dialog di progress
                    dialog.dismiss();


                }

                @Override
                public void onFailure(int reason) {

                    Log.d("CONNECT", "FAILURE");

                    //Toast.makeText(getApplication(), "PIPPO", Toast.LENGTH_LONG);

                    // Togli il dialog di progress
                    //dialog.dismiss();

                    // show failure to the user VANNO MESSI NEL BROIASCASTRECEIVER

                    // refresh peer list
                }
            });

        }
    }).start();
}

private void buildGroupAccessDialog(final String groupName) {

    AlertDialog.Builder alertDialogBuilder = new AlertDialog.Builder(
            this);

    // set title
    alertDialogBuilder.setTitle("Join group");

    // set dialog message
    alertDialogBuilder
            .setMessage("Do you want to join " + groupName + "  ?")
            .setCancelable(false)
            .setPositiveButton("Yes", new DialogInterface.OnClickListener() {
                public void onClick(DialogInterface dialog, int id) {
                    //join group
                    joinGroup(groupName);
                }
            })
            .setNegativeButton("No", new DialogInterface.OnClickListener() {
                public void onClick(DialogInterface dialog, int id) {
                }
            }).create()
            .show();
}

现在问题1)解决了,但我仍然无法关闭对话框。 有什么想法吗?